Prostate specific membrane antigen PET avidity in a granular cell tumour of the left supraspinatus muscle: a case report.

Granular cell tumour is a rare, mostly benign, soft tissue, neuroectodermal tumour, most commonly seen in the skin and peripheral soft tissue. There are no publications to date of PSMA-PET avidity in a granular cell tumour. In this 60 year old male, staging PSMA-PET for a localized intermediate risk prostate cancer incidentally identified a PSMA-avid left supraspinatus lesion, which was subsequently biopsy-proven as a granular cell tumour. We present the first case of PSMA-avid granular cell tumour and add to the growing literature documenting PSMA-PET avidity in benign and malignant lesions apart from prostate cancer.

Long-term outcomes of definitive radiation with volumetric modulated arc therapy and concurrent chemotherapy for squamous cell carcinoma of the anus in a regional Australian cancer centre.

INTRODUCTION: Concurrent chemoradiotherapy is the standard of care in the curative intent treatment of squamous cell carcinoma (SCC) of the anus. Volumetric arc therapy (VMAT) is a highly conformal radiation therapy technique that has been implemented to reduce toxicity for these patients. However, there are few reports evaluating the long-term outcomes of VMAT. Thus, we evaluated the survival and toxicity outcomes of anal cancer patients treated in our regional cancer centre undergoing curative intent chemoradiotherapy using VMAT and following the Australian EviQ guidelines. METHODS: All consecutive patients treated with the VMAT technique for curative-intent definitive chemoradiotherapy for anal SCC at our institution from 2013 until 2022 were retrospectively reviewed for survival and toxicity outcomes. Kaplan-Meier estimates of locoregional control, distant metastasis-free survival, disease-free survival, anal cancer-specific survival and overall survival were obtained. RESULTS: In total, 44 patients were analysed. The median follow-up was 48.9 months (Range 7.8-107). 97.7% of patients completed the prescribed radiation therapy and 88.6% chemotherapy. Five patients (11.4%) recurred. Four (9.1%) had isolated local failures, and one (2.3%) had an isolated distant failure. There were no regional nodal failures. The Kaplan-Meier estimates for locoregional control, distant metastasis-free survival, disease-free survival, anal cancer-specific survival and overall survival were 90.3%, 97.7%, 88.1%, 97.1% and 87% at 3 years, and 90.3%, 97.7%, 88.1%, 93.0% and 72.3% at 5 years, respectively. Acute grade 3 genitourinary (GU), gastrointestinal (GI) and skin toxicities occurred in 2.2%, 6.8% and 13.6% of patients, respectively. There were no acute grade 4 toxicities. Late grade 2 GU and GI toxicities occurred in 6.8% and 11.3% of patients, respectively. There were no late grade 3 or 4 toxicities or treatment-related deaths. The 5 -year colostomy-free survival rate was 86.4%. CONCLUSION: Outcomes for anal SCC after definitive chemoradiotherapy using VMAT in our regional cancer centre results in low rates of grade 3/4 toxicity, high rates of organ preservation and excellent survival outcomes.

Long-Term Survival After Definitive Concurrent Chemoradiation Therapy for Synchronous Small Cell Neuroendocrine Carcinoma of the Urinary Bladder and Adenocarcinoma of the Prostate: A Case Report.

Available reports of synchronous prostate and bladder cancer have exclusively described radical cystoprostatectomy with or without perioperative chemotherapy as the treatment of choice. There are no reports of curative intent or definitive chemoradiation therapy for synchronous primary bladder and primary prostate cancers. Small cell carcinoma of the bladder is a rare and aggressive tumor. We present the first case of synchronous mixed small cell carcinoma and urothelial carcinoma of the urinary bladder and adenocarcinoma of the prostate in a 70-year-old male who attained long-term survival after curative intent and definitive concurrent chemoradiotherapy with minimal acute and late toxicities. The patient remained alive and disease-free at 41 months post-treatment and achieved excellent functional outcomes with organ preservation. Definitive chemoradiation therapy offers a safe and effective, curative-intent organ preservation treatment for localized synchronous prostate and bladder cancers.

Lessons of Hope and Resilience: A Co-Produced Qualitative Study of the Experiences of Youth Living with Psychosis During the COVID-19 Pandemic in Nigeria.

Much of the emerging evidence on the impact of COVID-19 on people with psychosocial disabilities comes from high-income countries. This study sought to explore the perceptions and experiences of youths living with psychosis during the COVID-19 pandemic in Nigeria. Using a co-produced research process, a facility-based study was conducted among youth with confirmed diagnosis of a psychotic disorder. In-depth interviews were conducted with 20 participants. Data was transcribed, double-coded and analysed with Atlas.ti using a thematic analysis approach. We found that participants were aware of good evidence-based information on the nature of the disease and the pandemic. Many of them described worsening mental health and disruptions to daily routines. Opportunities for deepening family relationships, skill building, helping others, and extended time for previously neglected self-development activities were described. This study benefitted from co-production with persons with lived experience, which could be harnessed for future research on psychosis.

A Case Report of Kearns-Sayre Syndrome: Not an Absolute Contraindication for Radiotherapy.

Kearns-Sayre syndrome (KSS) is a rare mitochondrial disorder, and the effects of radiotherapy on such a population group are unknown. A 60-year-old male with a history of KSS was diagnosed with locally advanced basal cell carcinoma along the left inner canthus. He was treated at our institution with curative intent radiotherapy alone and tolerated it well with no major acute or late toxicities. There was a complete clinical and radiological response of the tumor, with no evidence of recurrence 2.5 years after treatment. Further research is needed to explore the effects of ionizing radiation on patients with mitochondrial DNA defects.

Prostate-specific membrane antigen positron emission tomography detected local failure after post-prostatectomy radiation therapy: Low rates of out-of-field recurrence validates current Australian prostate bed contouring guidelines.

INTRODUCTION: The Australian Faculty of Radiation Oncology Genitourinary Group (FROGG) developed prostate bed clinical target volume (CTV) contouring guidelines which were subsequently used to develop the National EviQ guidelines for adjuvant and salvage post-prostatectomy radiotherapy (PPRT). These guidelines were based mainly upon consensus agreement. With the advent of prostate-specific membrane antigen (PSMA) positron emission tomography (PET), sites of recurrence can now be detected with low prostate-specific antigen (PSA) levels following radical prostatectomy. We evaluated sites of recurrence in patients treated with FROGG/EviQ CTVs to inform upcoming modifications of these guidelines. METHODS: At our institution, we use the FROGG/EviQ guidelines for PPRT. From 2015, patients with PSA failure following PPRT have been re-staged using PSMA PET imaging. We identified patients with PET-avid local, nodal, and distant recurrences, fusing them with original treatment plans to determine whether recurrences were within or outside the prostate bed CTV. Regional nodal failures were reviewed to determine if they were within current elective node contouring guidelines. RESULTS: Ninety-four patients had positive PSMA PET following PPRT. Nine (9.6%) recurrences were local, seven being local-only. One local recurrence (1.1%) was just superior to the contoured prostate bed CTV, located within the vas deferens. Seventy-three (77.7%) patients had a component of node failure, with 56 (59.6%) having node-only failure. Sites of nodal relapses were covered by standard contouring guidelines 60.3% of the time. CONCLUSION: The low recurrence rate outside of current prostate bed CTV contouring guidelines is consistent with other studies using contemporary contouring, and validates the efficacy of the current FROGG/EviQ prostate bed CTV definition.

Patterns of practice regarding use of radiation therapy following radical prostatectomy: A survey of Radiation Oncologists and Urologists in Australia and New Zealand.

INTRODUCTION: This study aimed to investigate the patterns of practices of radiation oncologists (ROs) and urologists in Australia and New Zealand with respect to the utilisation of post-prostatectomy radiation therapy (RT) and help guide the development of an update to the existing Faculty of Radiation Oncology Genito-Urinary Group post-prostatectomy guidelines. METHODS: ROs and urologists with subspecialty practice in prostate cancer from Australia and New Zealand were invited to participate in an online survey comprised of clinical scenarios regarding post-prostatectomy RT. RESULTS: Sixty-five ROs and 28 urologists responded to the survey. In the setting of low-risk biochemical relapse, the threshold for initiating RT was lower for ROs than urologists. ROs were more likely than urologists to recommend adjuvant RT for node-positive disease. When salvage RT was advised for a pT3N0R1 recurrence, there was no consensus amongst ROs on whether to add either ADT or nodal treatment over prostate bed RT alone. For a solitary PSMA-avid pelvic lymph node recurrence, whole pelvis RT with androgen deprivation therapy was the preferred treatment option (72% ROs, 43% urologists). Most ROs (92%) recommended conventionally fractionated RT to 66-70 Gy, with a boost to any PSMA PET avid recurrent disease. CONCLUSION: This survey highlights the marked discordance in practice for the management of prostate cancer relapse post-prostatectomy. This is seen not only between specialties but also within the radiation oncology community. This emphasises the need for an updated evidence-based guideline to be produced.

Outcomes of dose-escalated IMRT and ADT in Octogenarians with prostate cancer.

INTRODUCTION: We evaluated long-term outcomes for octogenarians with localised prostate cancer treated using dose-escalated image-guided intensity-modulated radiation therapy (IMRT) at our institution. METHODS: The charts of octogenarians treated for localised prostate cancer were retrospectively reviewed. Overall survival (OS), prostate cancer-specific survival (PCaSS), toxicity rates and changes from baseline were collected. RESULTS: The median follow-up was 97 months. Of 107 eligible patients, 27.1% had intermediate-risk and 72.9% had high-risk localised prostate cancer. Median dose was 78Gy, and 97.2% received ADT. OS was 91.4% and 67.2% at 5 and 10 years. PCaSS was 98.0% and 88.7% at 5 and 10 years. In all, 39 (36.4%) of patients died, with the cause of death known in 30: in 26.7% of these patients, prostate cancer was the cause of death. Grade ≥ 2 late GI and GU toxicity was 0.9% and 24.3% respectively. In all, 11.2% and 22.4% of patients reported worsening of GI or GU function from baseline, and 13.1% and 21.5% reported improvement in GI and GU function compared to baseline. CONCLUSION: Selected octogenarian patients with localised prostate cancer appear to benefit from radiation therapy and ADT. Despite excellent long-term PCaSS, 26.7% of patients died of prostate cancer. Rates of GI and GU toxicity were acceptable, and deterioration of urinary and bowel function compared to baseline was just as common as improvement in function from baseline.

Androgen Receptor Status in Triple Negative Breast Cancer: Does It Correlate with Clinicopathological Characteristics?

Purpose: Triple negative breast cancer (TNBC) is a breast carcinoma subtype that neither expresses estrogen (ER) and progesterone receptors (PR) nor the human epidermal growth factor receptor 2 (HER2). Patients with TNBC have been shown to have poorer outcomes mainly owing to the limited treatment options available. However, some studies have shown TNBC tumors expressing androgen receptors (AR), raising hopes of its prognostic role. Patients and Methods: This retrospective study investigated the expression of AR in TNBC and its relationship with known patient demographics, tumor and survival characteristics. From the records of 205 TNBC patients, 36 had available archived tissue samples eligible for AR staining. For statistical purposes, tumors were classified as either "positive" or "negative" for AR expression. The nuclear expression of AR was scored by measuring the percentage of stained tumor cells and its staining intensity. Results: AR was expressed by 50% of the tissue samples in our TNBC cohort. The relationship between AR status with age at the time of TNBC diagnosis was statistically significant, with all AR positive TNBC patients being greater than 50 years old (vs 72.2% in AR negative TNBC). Also, the relationship between AR status and type of surgery received was statistically significant. There were no statistically significant associations between AR status with other tumor characteristics including "TNM status", tumor grade or treatments received. There was no statistically significant difference in median survival between AR negative and AR positive TNBC patients (3.5 vs 3.1 years; p = 0.581). The relationship between OS time and AR status (p = 0.581), type of surgery (p = 0.061) and treatments (p = 0.917) were not statistically significant. Conclusion: The androgen receptor may be an important prognostic marker in TNBC, with further research warranted. This research may benefit future studies investigating receptor-targeted therapies in TNBC.

PSMA-PET-guided dose-escalated volumetric arc therapy for newly diagnosed lymph node-positive prostate cancer: 5 Year outcomes following the FROGG and EviQ node-positive guidelines.

INTRODUCTION: The Royal Australian and New Zealand College of Radiologists (RANZCR) Faculty of Radiation Oncology Genitourinary Group (FROGG) guidelines and online EviQ protocols incorporate prostate-specific membrane antigen (PSMA) positron emission tomography (PET)-guided dose-escalated intensity-modulated radiation therapy (DE-IMRT) for newly diagnosed lymph node (LN) positive prostate cancer. We evaluated late toxicity and efficacy outcomes following the FROGG and EviQ approach. METHODS: Patients with LN-positive-only metastases on PSMA-PET imaging were offered curative therapy with 3 months neoadjuvant androgen deprivation therapy (ADT) followed by DE-IMRT and 3 years adjuvant ADT. IMRT was delivered via volumetric arc therapy (VMAT). We aimed to deliver 81 Gy in 45 fractions (Fx) to the prostate and PET-positive LNs, and 60 Gy in 45 Fx to elective pelvic nodes, contoured using the PIVOTAL guidelines. RESULTS: Forty-five patients were included. The median number of PET-positive nodes boosted was 2 (range 1-6) and median boost volume 1.16 cc (range 0.15-4.14). Seventeen (38%) patients had PET-positive nodes outside of PIVOTAL contouring guidelines. With 60 months median follow-up, disease-free, metastasis-free, prostate cancer-specific and overall survival were 88.1%, 95.3%, 100% and 91.5%. There were no in-field nodal failures. Late grade 1, 2 and 3 gastrointestinal toxicities occurred in 4%, 2% and 0% of patients, and genitourinary toxicity in 18%, 18% and 4%. Lower limb grade 2 lymphoedema occurred in three patients (7%). CONCLUSION: Outcomes following FROGG guidelines and EviQ are promising, with high long-term disease control and low toxicity. Contouring guidelines require modification due to the high rate of PET-positive nodes demonstrated beyond recommended coverage.

Preferences for accessing sexual health services among middle-aged and older adults in the UK: a study protocol for a discrete choice experiment using mixed methods.

INTRODUCTION: Sexual health is essential for general health and well-being. Sexual health services for middle-aged and older adults are not prioritised and optimising available services for this population is often overlooked. Not much is known about preferences for accessing sexual health services among middle-aged and older people or level of satisfaction with current services. The aim of this study is to explore preferences for seeking sexual health services among middle-aged and older adults in the UK. This study will use discrete choice experiments (DCEs) including initial qualitative interviews followed by the survey, which have been used as a tool to explore preferences in various health service delivery. METHODS AND ANALYSIS: The project will be carried out in two phases. First, we will conduct in-depth semi-structured interviews with 20-30 adults (aged 45+), including disabled people, and those from sexual minority groups resident in the UK. Interviews will explore indications, preferences and factors related to accessing sexual health services. Themes and subthemes emerging from the analysis of the interviews will then be used to design the choice sets and attribute level for the DCEs. For the second phase, for the DCEs, we will design choice sets composed of sexual health service delivery scenarios. The software Ngene will be used to develop the experimental design matrix for the DCE. We will use descriptive statistics to summarise the key sociodemographic characteristics of the study population. Multinomial logit, latent class and mixed logit models will be explored to assess sexual health service preferences and preference heterogeneity. ETHICS AND DISSEMINATION: Ethical approval for both parts of this study was granted by the Research and Ethics Committee at the London School of Hygiene & Tropical Medicine. Findings from this study will be disseminated widely to relevant stakeholders via scheduled meetings, webinars, presentations and journal publications.

Sexual behaviours and sexual health among middle-aged and older adults in Britain.

OBJECTIVES: Population-representative studies of the sexual health of middle-aged and older adults are lacking in ageing societies. This study aimed to identify latent patterns of sexual behaviours and health of people aged 45-74 years. METHODS: We conducted a latent class analysis of the National Attitudes and Sexual Lifestyles Survey (Natsal-3), a nationally representative survey conducted in Britain in 2011. RESULTS: Of the 5260 respondents aged 45-74 years, 48.86% of men and 44.91% of women belonged to the Content Caseys class who reported good sexual health. The Infrequent Indigos (30.94% of men, 44.38% of women) were characterised by a lack of sexual activity, reported some dissatisfaction, and were more likely to have a disability. The Low-Functioning Lees (11.65% of men, 8.41% of women) reported some more disability and had issues with sexual functioning and higher levels of distress. The Multiple-Partnered Morgans (8.62% of men, 2.30% of women) were characterised by a greater number of sexual partners and several risk behaviours. CONCLUSIONS: The use of these four classes can aid in improved targeting of tailored sexual health services to improve sexual function, sexual satisfaction, reduce distress and risky behaviours among middle-aged and older adults. These services should be inclusive of the disabled community.

No Increase in Acute or Late Radiation Toxicities in Patients With Ehlers-Danlos Syndrome Receiving Adjuvant Breast Radiation Therapy: A Report of Four Cases With Extended Follow-Up.

Ehlers-Danlos syndrome (EDS) consists of a heterogeneous group of congenital collagen formation disorders characterised by skin hyperextensibility, atrophic scarring, and generalized joint hypermobility. Collagen vascular disorders have been implicated in increased incidence and severity of radiation toxicities; however, there are limited reports on the safety of radiation therapy with EDS. We identified all patients with EDS who received adjuvant conventional and hypofractionated breast radiation therapy at our institution and reviewed patient, treatment, and toxicity characteristics. Four patients were identified with a median follow-up of 13.2 months. Acute toxicities were limited to grade 1 dermatitis in all four patients. No late toxicities were seen. In this report, radiation therapy to the breast with conventional and hypofractionated regimens resulted in no significant acute or late toxicity.

Sourcing thermotolerant poly(ethylene terephthalate) hydrolase scaffolds from natural diversity.

Enzymatic deconstruction of poly(ethylene terephthalate) (PET) is under intense investigation, given the ability of hydrolase enzymes to depolymerize PET to its constituent monomers near the polymer glass transition temperature. To date, reported PET hydrolases have been sourced from a relatively narrow sequence space. Here, we identify additional PET-active biocatalysts from natural diversity by using bioinformatics and machine learning to mine 74 putative thermotolerant PET hydrolases. We successfully express, purify, and assay 51 enzymes from seven distinct phylogenetic groups; observing PET hydrolysis activity on amorphous PET film from 37 enzymes in reactions spanning pH from 4.5-9.0 and temperatures from 30-70 °C. We conduct PET hydrolysis time-course reactions with the best-performing enzymes, where we observe differences in substrate selectivity as function of PET morphology. We employed X-ray crystallography and AlphaFold to examine the enzyme architectures of all 74 candidates, revealing protein folds and accessory domains not previously associated with PET deconstruction. Overall, this study expands the number and diversity of thermotolerant scaffolds for enzymatic PET deconstruction.

Bone health assessment with dual energy X-ray absorptiometry in men with high-risk prostate carcinoma commencing adjuvant androgen deprivation therapy.

Background: Androgen deprivation therapy (ADT) is a key component of therapy for patients with high-risk prostate carcinoma, but it may be deleterious for bone health. We sought to determine the frequency of dual energy x-ray absorptiometry (DXA) scanning in patients commencing adjuvant ADT for treatment of high-risk prostate cancer at a large integrated regional cancer centre. Material and methods: The electronic medical records (EMR) of all patients with high-risk prostate carcinoma commenced on adjuvant ADT between January 1, 2016 and December 31, 2017 at the Mid-North Coast Cancer Institute, Coffs Harbour, Australia were reviewed. Patients commenced on neoadjuvant ADT and long-term suppressive ADT for metastatic disease were excluded. The following data were obtained: socio-demographic information, prostate cancer data, ADT details and DXA results. Results: 188 men (mean age ± SD, 75.4 ± 7 years) were commenced on adjuvant ADT for a total duration (mean ± SD) of 23.4 ± 7 months. Most (n = 155/188, 82%) were commenced on leuprorelin acetate. While only 26/188 (14%) had a DXA scan performed prior to ADT, another 133 (71%) had a DXA scan at a median of 20 days (interquartile range 7-98), later. Of the 159 men with DXA readings, 76 (48%) were osteopaenic and 38 (24%) were osteoporotic by DXA criteria. Conclusion: A high level (85%) of DXA scanning in men commencing ADT for prostate cancer can be achieved at a regional centre. The high prevalence (72%) of low bone mass in our unselected cohort underscores the importance of routine DXA scanning to guide bone health management during ADT.

Prognostic Value of the Neutrophil-Lymphocyte Ratio in Triple Negative Breast Cancer Patients.

OBJECTIVE: To assess the prognostic value of the neutrophil-lymphocyte ratio (NLR) in a cohort of triple-negative breast cancer patients (TNBC) treated in a regional cancer center. METHODS: The electronic medical records of 214 consecutive patients treated with surgery, chemotherapy, and radiotherapy between 2006 and 2016 were reviewed. The prognostic significance of the NLR for disease-free survival (DFS) and overall survival (OS) was examined in relation to clinical and treatment-related factors. Overall survival and DFS were assessed using the Kaplan-Meier method; Cox semi-parametric regression modelling was used for multivariate analysis. RESULTS: Ninety patients were eligible; median follow-up was 45.6 months (range, 6-105 months). The 3-year OS rate was 77.9% and the 5-year OS rate 61.7%. Patients with an NLR of ≤1.7 had significantly better DFS (P=0.029) than patients with an NLR>1.7; OS approached statistical significance (P=0.055). When treatment-related factors - significant on univariate analysis - were entered into the multivariate model, only nodal status N2/N3 remained as significant for DFS (P=0.0078) and advanced T-stage (T3, T4) significant for OS (P=0.014). CONCLUSION: While NLR is associated with survival in TNBC patients on univariate analysis, the prognostic value of NLR is likely due to its association with other clinicopathological factors.

Evaluation of apical clips placed during axillary dissection demonstrates potential under-coverage of axillary radiation therapy target volumes during breast cancer regional nodal irradiation.

INTRODUCTION: Evidence-based Australian guidelines (eviQ) recommend adjuvant supraclavicular fossa irradiation after axillary lymph node dissection (ALND) in node-positive breast cancer patients. Disparity between surgically determined versus computed tomography (CT) determined nodal volumes may result in discontiguous nodal volumes and untreated nodal tissue. We examine the extent of untreated nodal tissue in women with breast cancer post-level II or III ALND and adjuvant radiation therapy (RT) using ESTRO contouring guidelines. METHODS: Female breast cancer patients who underwent level II and III ALND with apical clip placement from 2016 to 2020 and CT simulated in supine position were included. CT-defined axillary level II-IV volumes were contoured using ESTRO guidelines. The distance between the apical clip and RT nodal volumes was measured to indicate extent of untreated tissue. RESULTS: Of 34 eligible patients treated by 7 surgeons, 76% had level II ALND and 24% level III ALND. Only 5.9% of clips entirely encompassed the corresponding RT nodal volumes. 55.9% of clips fell within and 44.1% fell inferolaterally outside the corresponding RT nodal volumes. A median 3.6 cm (range 0-7.5 cm) of undissected nodal tissue would not be included within standard RT target volumes following eviQ recommendations. CONCLUSION: There is a disparity between surgically determined versus CT determined axillary nodal volumes, leading to discontiguous nodal volumes and untreated axillary nodal tissue, despite following standard radiation contouring guidelines. Intraoperatively placed apical axillary clips may assist radiation oncologists to accurately delineate undissected nodal tissues at risk.

Comparative Performance of PETase as a Function of Reaction Conditions, Substrate Properties, and Product Accumulation.

Invited for this month's cover is the BOTTLE Consortium, featuring Gregg Beckham's laboratory from NREL and John McGeehan's laboratory from the University of Portsmouth. The cover image shows the application of poly(ethylene terephthalate) (PET) hydrolase enzymes on post-consumer waste plastic, towards the development of an enzymatic PET recycling strategy. The Full Paper itself is available at 10.1002/cssc.202101932.

Comparative Performance of PETase as a Function of Reaction Conditions, Substrate Properties, and Product Accumulation.

There is keen interest to develop new technologies to recycle the plastic poly(ethylene terephthalate) (PET). To this end, the use of PET-hydrolyzing enzymes has shown promise for PET deconstruction to its monomers, terephthalate (TPA) and ethylene glycol (EG). Here, the Ideonella sakaiensis PETase wild-type enzyme was compared to a previously reported improved variant (W159H/S238F). The thermostability of each enzyme was compared and a 1.45 Šresolution structure of the mutant was described, highlighting changes in the substrate binding cleft compared to the wild-type enzyme. Subsequently, the performance of the wild-type and variant enzyme was compared as a function of temperature, substrate morphology, and reaction mixture composition. These studies showed that reaction temperature had the strongest influence on performance between the two enzymes. It was also shown that both enzymes achieved higher levels of PET conversion for substrates with moderate crystallinity relative to amorphous substrates. Finally, the impact of product accumulation on reaction progress was assessed for the hydrolysis of both PET and bis(2-hydroxyethyl) terephthalate (BHET). Each enzyme displayed different inhibition profiles to mono(2-hydroxyethyl) terephthalate (MHET) and TPA, while both were sensitive to inhibition by EG. Overall, this study highlights the importance of reaction conditions, substrate selection, and product accumulation for catalytic performance of PET-hydrolyzing enzymes, which have implications for enzyme screening in the development of enzyme-based polyester recycling.